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(11) | EP 0 284 347 A3 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | A device for inspecting the degree of vacuum in a sealed vessel |
| (57) A device for inspecting the degree of vacuum in a sealed vessel is disclosed in which
a high degree of accuracy is not required for positioning of an object vessel (14)
and in which the degree of vacuum of an object vessel (14) can be detected with a
high S/N ratio under a reduced influence of fluctuations in size or configuration
of a top (lid) wall (15a) of an object vessel (14). The device comprises a large diameter
lens (4) for refracting rays of light from a light source (2) into rays of light to
be irradiated upon an area including a lid wall (15a) of a sealed vessel (14) held
at a predetermined inspection position, a beam splitter (5) for passing part of rays
from the large diameter lens (4) therethrough and for reflecting reflected rays (13a)
from the lid wall (15a) of the sealed vessel (14), a condenser lens (6) for condensing
reflected rays from the beam splitter (5), an image sensor (7) for detecting the thus
condensed rays, and a comparator circuit (21) for comparing an output voltage of the
image sensor (7) with a reference voltage to develop a signal representing whether
the sealed vessel (14) is acceptable or is to be rejected. |